Method and apparatus for detecting free fall

ABSTRACT

A data processing system including a data storage device having data stored on a data storage medium. Within said data processing system, a system electronics is operatively coupled to a sensor and to said data storage device. When the sensor senses a change in gravitational or inertial acceleration of said data processing system, it alerts system electronics to temporarily park a read/write head in a safe position.

This application is a continuation application of U.S. patentapplication Ser. No. 10/348,465, filed on Jan. 21, 2003, now U.S. Pat.No. 6,768,006, which is a divisional application of U.S. patentapplication Ser. No. 09/678,541, filed on Oct. 2, 2000, now issued asU.S. Pat. No. 6,520,013.

FIELD OF THE INVENTION

This invention relates to data storage devices, such as hard disc driveassemblies and data processing systems, generally. In particular, theinvention relates to data storage devices that are subject to free fallor other changes in acceleration, for example, storage devices used inportable computers, cameras, onboard vehicular computers, and similarelectronic devices. ‘Free fall’ produces a change in the force, i.e.acceleration, of gravity as perceived in the frame of reference in whichthe data storage device is at rest.

BACKGROUND

Portable electronics devices such as digital and film cameras, notebookcomputers, and onboard vehicular computers containing data storagedevices such as hard disk drives are often dropped, bumped, or bounced.When an object is dropped or falls back to earth after a bounce, theobject experiences free fall, a period of minimal or zero gravitationalforce. ‘Free fall’ produces a change in the force, i.e. acceleration, ofgravity as perceived in the frame of reference in which the data storagedevice is at rest. On earth, free fall usually immediately precedes animpact with a surface that may damage operating or unparked data storagedevices, their spinning disks, actuators, and read/write heads. A parkeddata storage device is one in which the actuator has temporarily movedthe head away from the spinning disk, and the actuator and head aresafely locked in a fixed position in preparation for transportation oran anticipated impact. Because a data storage device can be safelyprepared for an impact in a time shorter than the time it takes the datastorage device to complete its fall, the present invention has greatutility in preventing or mitigating the damage formerly experienced bydata storage devices that were dropped down stairs, dropped ontoconcrete, asphalt or other hard surfaces, or that were bounced into theair from vehicles contacting speed bumps, waves, or turbulent airpockets at high speeds and slammed back down again.

In simplest form, a data storage device, such as a disc drive, consistsof a spinning disk and an actuator movably positioned near the surfaceof the disk. The surface of the disk typically contains multiple annulartracks or grooves in which data is stored and manipulated and from whichdata is retrieved by a read/write head (e.g. a magnetic or an opticalhead) positioned on the actuator.

It is important that the data storage head be kept as free fromvibrations and/or sudden acceleration or deceleration as possiblebecause the head reads data from and writes data to the multiple annulartracks on the spinning disk. Sudden acceleration or deceleration orexcessive vibration of the disk drive can cause the head to skip tracks,to encode information incorrectly on the wrong track or tracks, to erasedata previously encoded on the disk, or to dent the disk surface.Several types of sensors have been developed to mitigate or to preventexcessive vibration from harming recorded data, but no sensors measuringchanges in the force, i.e. acceleration, of gravity in the frame of thedata storage device, existed prior to conception and development of thisinvention.

One type of vibration detection and protection system found in the fieldof data storage devices is known as the off track signal or OTS.Generated by an electrical component of a data processing system, suchas a magnetic hard disk, or CD, or DVD drive, the OTS is derived fromthe signals generated by the magnetic hard disk or CD head as it followsdata tracks on the disk. The amplitude of the OTS is designed to vary indirect proportion to the amount of vibration experienced by the dataprocessing system. Thus, the more vibration experienced by the dataprocessing system, the more the amplitude of the OTS increases. Thesystem electronics of the data storage device monitors the amplitude ofthe OTS and temporarily disables the ability of the head to write and/orread information to or from the data storage device whenever the OTSamplitude matches or exceeds a predetermined amplitude.

Although the OTS system protects data stored on the data storage devicefrom being erased or overwritten by the head, it does not prevent damageresulting from the head popping up and down onto the spinning disk whenthe data storage device is dropped and impacts a surface. For example,if the head slams downward onto a spinning data medium device, such as aCD or DVD or magnetic hard disk, data may be irretrievably lost, thehead may be severely damaged, and the CD, DVD, or magnetic hard disk maybe irreparably dented.

A second kind of sensor is found in the unrelated automobile field.Sensors in this field are used to deploy various safety devices, such asairbags, whenever an accident occurs. Such sensors passively wait for animpact to occur and then rapidly deploy safety devices before a human'sbody impacts hard, bone-crushing surfaces within the automobile'sinterior cabin such as dashboards, windshields, and steering wheels.They cannot predict the possibility of an imminent impact, nor can theydetect the absence of a gravitational field as some embodiments of thepresent invention can. Moreover, sensors found in the automobile fieldhave not been used to protect data in data processing systems such ashard disk drives.

A third type of vibration countermeasure found in the field of consumerportable electronic devices is specifically designed to combat the“skips” commonly associated with audio playback of CD-ROMS and DVD's.“Skips” are miniature, but discernable, periods of silence in music orother audio broadcast material that occur whenever a musical playbackdevice is jostled, vibrated, or dropped. This countermeasure istypically called a “buffering system.” In simplest form, a bufferingsystem incorporated within a musical playback device reads audio datafrom the spinning disk during playback of the disk at a rate slightlyfaster than the rate at which the audio data is broadcast. By reading“ahead” of the broadcast, a portion of the audio data is continuallysaved up and stored in the buffer. Whenever a “skip” occurs, thebuffering system ensures a smooth, unbroken audio playback by fillingthe “skip” with audio data from the buffer. Unlike, the presentinvention, however, the buffering system does not protect the datastorage device or its data actuating head from damage caused by droppingor vibrating the device.

SUMMARY OF THE INVENTION

In a preferred embodiment of the present invention, as illustrativelydescribed herein, a data processing system is provided. Within the dataprocessing system, system electronics is operatively coupled to a harddisk drive assembly and to an acceleration sensor, which can sensegravitational acceleration. The system electronics monitors theacceleration sensor to determine whether the sensor's switch is open orclosed. If an open switch indicating a free fall is detected, the systemelectronics protects the data read/write head and data storage medium bytemporarily parking the head in a safe position where it cannot impactthe data storage medium surface. A safe position can include a parkedposition off to one side of a data storage medium or a secured operatingposition that prevents vibration from damaging the read/write head orthe data storage medium. According to one aspect of the presentinvention, the term secured includes fixed, semi-fixed, and movableoperating positions.

According to an alternate aspect of the present invention, a sensor isprovided that can detect changes in gravitational and/or inertialacceleration. In an exemplary embodiment, the sensor includes anelectrically conductive tube having two ends. A supporting material mayclose one end of the tube. The other end may be open or closed. Withinthe interior of the tube, one end of a flexible beam or wire is insertedinto the supporting material. Gravity flexes the opposite end of thebeam or wire into contact with the tubular case, creating a closedelectrical circuit. Whenever the force of gravity lessens, the secondend of the beam or wire breaks contact with the tube, creating an openswitch.

According to another aspect of the present invention, a sensor isprovided that can detect changes in gravitational and/or inertialacceleration. Illustratively, this sensor includes a closed cylinder.Within the interior of the cylinder, a centrally positioned,electrically conductive beam juts upward from the cylinder's base. Acircle of insulating material surrounds the base of the beam and createsa gap between the beam and the cylinder's oblique, conical interiorwalls. The beam and cylinder walls are electrically conductive. Gravityholds an electrically conductive sphere in contact with both the beamand a oblique surface, creating a closed circuit. Any lessening of thegravitational force causes the sphere to break contact with either orboth of the beam and interior walls, creating an open circuit.

Various examples for practicing the invention, other advantages, andnovel features thereof will be apparent from the following detaileddescription of various illustrative preferred embodiments of theinvention, reference being made to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the figures of the accompanying drawings in which likereferences indicate similar elements.

FIG. 1 is an exemplary view of a data processing system in free fall. Asshown, the data processing system contains a hard disc operativelycoupled to a read/write head. An embodiment of the present invention hassensed free fall and safely parked the actuator and magnetic head priorto impact.

FIG. 2 is a schematic illustrating how system electronics within a dataprocessing system can monitor an embodiment of the present invention andcommand a data storage device, such as a hard disc drive, to park anactuator and magnetic head when a state of free fall is detected.

FIG. 3 illustrates an exemplary embodiment of the present invention inthe at rest state according to one aspect of the present invention.

FIG. 4 illustrates an exemplary embodiment of the present invention in astate of free fall according to an aspect of the present invention.

FIG. 5 illustrates a data storage device; such as a hard disc drive, andits associated actuator and magnetic head in operation. Dotted linesindicate the parked position of the actuator and head.

FIG. 6 illustrates an exemplary embodiment of the present invention inthe at rest state according to another aspect of the invention

FIG. 7 illustrates an exemplary embodiment of the present invention in astate of free fall according to another aspect of the invention.

FIG. 8A is a side view illustrating an exemplary embodiment of thepresent invention in the at rest state according to another aspect ofthe present invention.

FIG. 8B is a side view illustrating an exemplary embodiment of thepresent invention in a state of free fall according to another aspect ofthe present invention.

FIG. 8C is an overhead view illustrating an exemplary embodiment of thepresent invention in the at rest state according to another aspect ofthe present invention.

FIG. 8D is an bottom view illustrating an exemplary embodiment of thepresent invention.

DETAILED DESCRIPTION

The acceleration sensor shown illustratively in the accompanyingdrawings is particularly suited to be of relatively small size for usein data processing systems used in notebook computer systems, digitalcameras, music recording and playback devices, automobiles, marinevessels, aircraft, spacecraft, and similar equipment. Additionally, theembodiments of the present invention may be especially suited for use ina variety of additional applications not having data storage devicescoupled to actuators and heads where it is desired to sense accelerationor detect a state of free fall. For example, this invention could beused to trigger inflation of a cushion to soften the impact for adropped camera.

FIG. 1 shows a perspective view of a hard drive system. Typically, adata storage device 103, such as a hard disc drive system, is installedwithin a main housing of a computer 100, such as the notebook computerillustratively shown. However, it is understood that the invention isnot limited to computers such as the one illustratively shown in FIG. 1.Rather, the invention applies to and may complement any data storagedevice 103 wherever such device is located. For example, and forpurposes of illustration only and not limitation, a data storage device103, such as a hard disc drive, may be located within a camera or otherportable consumer electronic device, within an onboard vehicularcomputer, an elevator, an amusement park ride, etc. Moreover, in otherembodiments, the data storage device may store analog data instead ofdigital data and the data storage device may use optical mechanisms toread and/or write the data.

A data storage device 103, such as a hard disc drive, contains a datastorage medium 102 such as a hard disc and an actuator 104 having amagnetic read/write head 106. Read/write head 106 reads and writes datato tracks 108 on spinning data storage medium 102, such as a hard disc.Acceleration sensor 110 and system electronics 112 are electricallycoupled to the hard disc drive 103 such that when acceleration sensor110 detects a state of free fall in which there is substantially zeroperceived gravitational acceleration, system electronics 112 commandsthe disc drive 103 to put the actuator 104 and magnetic (or optical)head 106 in a parked position before the fall is completed.Alternatively, sensor 110 can be used to detect changes innon-gravitational (inertial) acceleration, an acceleration orde-acceleration of the sensor's reference frame caused objects such asautomobile or aircraft engines or vehicular brakes.

Preferably, acceleration sensor 110 is located near or at the center ofmass of the object prone to free fall so that sensing of the free fallstate will be independent of any rotation and centrifugal forces presentduring the fall. However, the invention includes all positions ofacceleration sensor 110 and all locations for system electronics 112that perform the monitoring and command functions described above.Illustratively, acceleration sensor 110 may be positioned as an integralcomponent of data storage device 103 itself, or may be positioned as anon-integral component of data storage device 103 elsewhere within adata processing system.

In a preferred embodiment, acceleration sensor 110 is integrated with adata processing system containing a hard drive disk assembly 103. In apreferred embodiment, sensor 110 is incorporated within system bysoldering leads 120 and 122 to pads on a substrate 124, for example, aprinted circuit board.

FIG. 2 shows a schematic representation illustrating how systemelectronics 112 monitors acceleration sensor 110 and commands datastorage device 103, such as a hard disc drive to park actuator 104 andmagnetic head 106 in a safe position when a free fall is indicated orthe gravitational force otherwise approaches zero.

Acceleration sensor 110 is a simple electronic switch that remainsclosed when system 100 is at rest, and opens when system 100 begins tofree fall. System electronics 112 continuously or periodically monitorsacceleration sensor 110 to detect whether the switch is closed or open.Immediately upon detecting an open switch, system electronics 112transmits a command to data storage device 103. Upon receiving thiscommand, data storage device 103 immediately parks actuator 104 andmagnetic head 106 in a safe position 126, as shown in FIG. 5. Safeposition can be either a location to the side of data storage medium102, as illustrated in FIG. 5, or a locked operating position thatprevents head 106 from writing to the wrong track 108 and that preventshead 106 from vibrating against data storage medium 102. For example, inan optical drive, a safe position 126 could be a location where theobjective lens is pinned against its upper stop.

FIG. 3 shows a cross-sectional side view of a preferred embodiment ofacceleration sensor 110. Sensor 110 includes a casing connection 116 anda beam connection 118. Casing connection 116 is connected to a firstlead 120, and beam connection 118 is connected to a second lead 122.FIG. 3 shows sensor 110 in an at rest position. In this position,gravity pulls electrically conductive mass 128, attached to one end ofelectrically conductive beam 130, into contact with electricallyconductive casing 132. Preferably, one end of beam 130 is supported byinsulating support material 138, which may be flexible or rigid. In theillustrated embodiment, insulating support material 138 is rigid.

Beam 130 may have any aspect ratio, meaning that beam 130 can have anycross-sectional shape. As exemplified in FIG. 3, beam 130 is flexibleand electrically conductive. Preferably, the flexural constant of beam130 is such that mass 128 contacts casing 132 when acted on by agravitational force. Specifically, the flexural characteristics of thebeam should be chosen so that two conditions are met:

-   -   1. The at rest gravitational force bends the beam, or        beam/flexible mount combination, so that the beam or beam/mass        makes electrical contact with the casing.    -   2. The lack of gravitational force during free fall allows the        beam or flexible mount to straighten and break the electrical        contact between the beam or beam/mass and the casing.

In a preferred embodiment, insulating support material 138 is a rigidmaterial such as glass, but other insulating materials such as plastic,epoxy, ceramic, etc. may also be used.

In an exemplary embodiment, free end of the beam 130 may be weightedwith a mass 128 to increase gravitational deflection and flex beam 130such that the mass 128 contacts the electrically conductive casing 132.However, the invention can operate without mass 128. For example, in anillustrative embodiment, the shape of the beam 130, its dimensions, andthe material comprising the beam 130 can be chosen such that the weightof the cantilevered portion of beam 130 itself flexes the free end ofbeam 130 into contact with a electrically conductive casing 132.

If a mass is attached to the free end of beam 130, the mass 128 may takealmost any size and shape since the size and shape of the mass 128 arenot essential to the operation of the invention. It makes no differencewhether the shape of the mass 128 is circular, squarish, polygonal, ortriangular, as long as the mass is made of or carries an electricallyconductive material and contacts electrically conductive casing 132 whenthe data storage device 103 is at rest. The preferable shape of the mass128, as illustratively shown in the Figures is spherical.

According to one aspect of the present invention, the beam 130 and mass128 are made of conductive materials or carry conductive means. Thus,electrical contact is made whenever either the free end of beam 130 ormass 128 touches casing 132. In this manner, the invention acts as anelectrical switch, closed when at rest and open when in free fall. Beam130 and mass 128 may be formed as one piece of electrically conductivematerial, or from separate pieces joined together by any suitablemethod, including, but not limited to, screwing, gluing, soldering, etc.

It should be noted that the dimensions of the components of accelerationsensor 110 are scalable, meaning of course, that one skilled in the artcan determine the mechanical coefficients of non-electrically conductiveinsulating material 138 and beam 130 easily and without undueexperimentation. Accordingly, one skilled in the art could readilymanufacture acceleration sensor 110 illustrated in FIGS. 1-3 in any oneof a number of possible sizes. In a preferred embodiment, however,acceleration sensor 110 is approximately 4-6 mm long, 2-3 mm wide and2-3 mm high. These preferred dimensions, however, are given only forpurposes of illustration, and are not meant to limit the size ofacceleration sensor 110 in any fashion. Rather the invention includesall sizes of acceleration sensor 110.

Preferably, as illustratively shown in FIG. 3, the sensor 110 describedabove is enclosed by a tubular casing 132 formed of an electricallyconductive material. In an exemplary embodiment, insulating supportmaterial 138 completely fills one end of the tubular casing, while thesecond end is also closed. The interior of casing 132 may be filled witha gas of the type well known in the art for sealing the interiors ofelectronic components to prevent corrosion of electrical contacts.However, it is not necessary to close the second end of the casing, noris it necessary that the casing be tubular. Rather, the second end ofthe casing may be left open, and the casing may take almost anystructural form, including, but not limited to tubes, circles, squares,triangles, polygons, etc. In a preferred embodiment, one end of casing132 is connected to the first electrically conductive lead 122, whilethe beam connection 118 is connected to a second electrically conductivelead 120.

In an alternative embodiment, the present invention may be made andoperated without a tubular casing 132. For example, fixed end of beam130 could be supported by insulating support member 138 and operativelyconnected via beam connection 118 to electrically conductive lead 120,such that the free end of beam 130 or mass 128 was positioned to makephysical contact with an electrically conductive pad when the datastorage device 103 is at rest.

FIG. 4 shows acceleration sensor 110 in a free fall position. In theabsence of a gravitational force (e.g. during free fall), physicalcontact with the casing 132 is broken as the beam 130 straightens to anapproximately horizontal position shown in FIG. 4. Thus, sensor 110functions as a switch, closed when at rest, open when in free fall.Breaking physical contact with casing 132 immediately alerts systemelectronics 112 (shown in FIG. 1) to command data storage device 103,such as a hard disc drive (FIG. 1) to park actuator 104 (FIG. 1)containing magnetic read/write head 106 (FIG. 1) in a safe position 126(shown in FIG. 5). Alternatively, the same method may be used withanother embodiment of the present invention in which mass 128 makeselectrical contact with casing 132. In such an embodiment, the switchwould be open in the at rest position and closed during free fall. Fromrest, an object within the Earth's gravitational field free falls 0.5meters in 0.32 seconds. The time required to process a command and parkthe head in a disc drive is typically less than 0.04 seconds. Thus, thehead can be parked in a safe position well before the fall is completed.

FIG. 5 is a top-down view of hard disk drive showing actuator 104 andmagnetic read/write head 106 in an operating position. A safe parkedposition 126 is indicated by broken lines. Data storage device 103, suchas a hard disc drive is operatively coupled to system electronics 112(not shown). In response to commands from system electronics 112, datastorage device 103 moves actuator 104 and magnetic read/write head 106rapidly sideways in a plane approximately parallel to the disk 102between its operating position and a parked position, which isillustratively depicted as safe position 126 in FIG. 5.

FIG. 6 is a side view of sensor 110 according to a preferred embodimentof the present invention. In this Figure, sensor 110 is shown at rest ina gravitational field. In this embodiment, beam 230 is rigid. One end ofbeam 230 is inserted into insulating support material 238, while theother end is attached to mass 228. Mass 228 may be of any shape, butpreferably is spherical. According to one aspect of the presentinvention, insulating support material 238 is flexible and adheres toelectrically conductive beam connection 218, which is also flexible.Illustratively, insulating non-electrically conductive support material238 is a semi-rigid or flexible material such as rubber.

When at acceleration sensor 110 is at rest, gravitational force pullsfree end, including mass 228, of rigid electrically conductive beam 230into contact with electrically conductive casing 232. When tilted by agravitational force, rigid beam 230 deforms insulating support material238 as shown. In an exemplary embodiment according to one aspect of theinvention, beam 230 and support material 238 may both be flexible.

FIG. 7 illustratively shows sensor 210 during free fall, a period ofminimal gravitational acceleration. During free fall, minimalgravitational acceleration and the restoring forces in deformedinsulating support material 238 cause mass 228 to break contact withcasing 232 and to return approximately to a position delineated byhorizontal axis 227.

FIG. 7 shows an illustrative embodiment of the present invention inwhich beam 230 is formed of a rigid, electrically conductive material.In this embodiment, rigid beam 230 is capable of moving between anat-rest position and a free-fall position. Preferably, rigid beam 230 issupported at one end by a semi-rigid or flexible, non-electricallyconductive insulating support material 238.

FIGS. 8A-8D show various views of an acceleration sensor according toparticular exemplary embodiments of the present invention. FIG. 8A is across-sectional side view of a gravitational acceleration sensor 110. Inthis illustrative embodiment, acceleration sensor 110 includes a casing332, which rests on non-conducting insulating base 338, an electrode330, and a spherical mass 328. This embodiment, like others previouslydescribed, acts as an electrical switch, closed when the sensor is atrest and open during free fall. In the at rest position, mass 328contacts both beam 330 and casing 332. During free fall, mass 328 doesnot contact beam 330 and case 332. The phrase “does not contact beam 330and case 332” further includes situations where: mass 328 contactscasing 332 only; mass 328 contacts beam 330 only; or mass 328 does notcontact beam 330 or casing 332.

Non-conducting insulating base 338 may be formed of any suitableinsulating material known in the art. The insulating material may beeither fixed or semi-rigid. In a preferred embodiment, insulating base338 may be made as thick or as thin as practicable. Conducting innerelectrode 330 (hereinafter beam 330) is vertically positioned ininsulating base 338. According to an aspect of the present invention, atop portion of beam 330 juts out into internal cavity 312 of casing 332,while a middle portion passes through insulating base 338. A bottomportion of beam 330, (hereinafter first conducting pin 320) extends pastthe exterior of insulating base 338 and removably inserts into asubstrate such as a printed circuit board 324. Similarly, a secondconducting pin 322, vertically positioned substantially parallel to beam330, also extends past the exterior of insulating base 338 and removablyinserts or connects into a substrate such as a printed circuit board324. Electrically conductive traces 333 and 334 connect sensor 310 tosystem electronics 112 (not shown), which monitor sensor 310 and commanddata storage device 103 (not shown) to park the magnetic or optical headwhenever conducting ball 328 (hereinafter mass 328) breaks electricalcontact between beam 330 and casing 332.

According to an aspect of the present invention, beam 330, conductingpins 320 and 322, mass 328, and casing 332 are each made of or carryelectrically conductive materials. Examples of such electricallyconductive materials include, but are not limited to: copper, brass,silver, gold, steel, and similar materials.

According to another aspect of the present invention, a bottom portionof the interior of casing 332 is angled to form an oblique surface 314,which extends from a point approximately located at horizontal axis 307down to insulating base 338 such that a ringed gap 340 encircles beam330. In a preferred embodiment, mass 328 is a sphere and gap 340 is notgreater than the diameter of mass 328. Gap 340 has a width sufficientthat mass 328 contacts both casing 332 and beam 330 simultaneously whensensor 110 is at rest, and a width sufficient that insulating base 338insulates beam 330 from casing 332. Illustratively, oblique surface 314angles downwards at approximately a 45 degree angle to channel mass 328into electrical contact with beam 330 when mass 328 is acted upon by agravitational force. However, oblique surface 314 may be sloped atalmost any angle less than 90 degrees so long as it channels mass 328into electrical contact with beam 330. According to another aspect ofthe invention, the interior and exterior surfaces of casing 332 arecylindrical, while the exterior of casing 332 may be of any shape.Internal cavity 312 may be filled with an inert gas or non-conductingliquid to prevent corrosion of beam 330, casing 332, and mass 328. Asused herein “mass 328” means contactor.

FIG. 8B illustrates how sensor 310 operates in the absence of agravitational force. The unique oblique interior walls 314 permit themass 328 to break away from the beam 330 and/or casing 332 when theforce of gravity is reduced to zero by free fall of the device. An opencircuit between the beam 330 and casing 332, implying the absence of agravitational force, signals system electronics 112 (FIG. 1) to commandhard disk drive 103 (FIG. 1) to park magnetic data actuating head 106(FIG. 1) in a safe position 126 (FIG. 5).

FIG. 8C is a top-down view of gravitational sensor 310 illustrativelyshowing how oblique surface 314 holds mass 328 in contact with beam 330when sensor 310 is acted upon by a gravitational force. In this view,the top cover of sensor 310 has been removed.

The illustrative dimensions of sensor 310 and its components are nowdescribed. According to an aspect of the present invention, the diameterof casing 332 is approximately 10 mm, the depth, approximately 5 mm. Thediameter of mass 328 measures approximately 2 mm, while the diameter ofbeam 330 measures approximately 2 mm. The diameter of the ringed gap 340of insulating material 338 surrounding beam 330 measures approximately 3mm. It will be understood that these ranges are provided only forpurposes of illustration. The diameter of the sensor 310 and thediameters of its components are free design parameters. The values shownor described are informative and exemplary only and should not beconstrued as limiting the invention in any way.

FIG. 8D shows a bottom view a gravitational sensor according to anaspect of the present invention. In this exemplary embodiment, firstconductive pin 320 is centrally mounted within insulating base 338.Illustratively, second conductive pin 322 may be positioned anywherewithin or without the circumference of insulating base 338 providedsecond conductive pin 322 does not electrically contact first conductivepin 320.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description, and is notintended to be exhaustive or to limit the invention to the precise formdisclosed. The description was selected to best explain the principlesof the invention and practical application of these principles to enableothers skilled in the art to best utilize the invention in variousembodiments and in various modifications as are suited to the particularuse contemplated. It is intended that the scope of the invention not belimited by the specification, but be defined by the claims set forthbelow.

1. A portable electronic device, comprising: a data storage devicehaving data stored on a data storage medium; and an accelerationdetector coupled to the data storage device to detect a change in anacceleration of the portable electronic device and to configure the datastorage device from a first operating state into a second operatingstate in response to the detection, wherein the acceleration detectorincludes a flexible non-electrically conductive support material, anelectrically conductive casing coupled to the flexible non-electricallyconductive support material, and a beam having a first end and a secondend supported by the flexible non-electrically conductive supportmaterial.
 2. The portable electronic device of claim 1, wherein theportable electronic device is a digital camera.
 3. The portableelectronic device of claim 1, wherein the portable electronic device isa musical playback device.
 4. The portable electronic device of claim 1,wherein the portable electronic device is a portable computer system. 5.The portable electronic device of claim 1, further comprising systemelectronics coupled to the data storage device and the accelerationdetector, wherein in response to the detection, the system electronicsexecute a predetermined process, which in part transforms the datastorage device from the first operating state into the second operatingstate.
 6. The portable electronic device of claim 5, wherein thepredetermined process, when executed, transforms the data storage devicefrom the first operating state into the second operating state.
 7. Theportable electronic device of claim 1, wherein during the secondoperating state, data stored in the data storage device is inaccessible.8. The portable electronic device of claim 1, wherein the beam is rigidor flexible.
 9. The portable electronic device of claim 8, wherein thesecond end of the beam contacts the casing when the accelerationdetector is at rest.
 10. The portable electronic device of claim 8,wherein the second end of the beam does not contact the casing duringfree fall.
 11. The portable electronic device of claim 8, wherein theacceleration detector further comprises a mass attached to the secondend of the beam.
 12. The portable electronic device of claim 11, whereinthe mass contacts the casing when the acceleration detector is at rest.13. The portable electronic device of claim 12, wherein the mass, thecasing, and the beam are each electrically conductive.
 14. The portableelectronic device of claim 11, wherein the mass does not contact thecasing when the acceleration detector is at rest.
 15. The portableelectronic device of claim 8, further comprising means to couple theacceleration detector to a substrate.
 16. The portable electronic deviceof claim 15, wherein the means is one of at least one lead or oneconductive pin.
 17. The portable electronic device of claim 1, whereinthe casing is closed at both ends and filled with an inert gas ornon-electrically conductive liquid.
 18. A method performed by a portableelectronic device, the method comprising: detecting a change in anacceleration of the portable electronic device using an accelerationdetector disposed within the portable electronic device; and executing apredetermined process in response to the detection, wherein theacceleration detector includes a flexible non-electrically conductivesupport material, an electrically conductive casing coupled to theflexible non-electrically conductive support material, and a beam havinga first end and a second end supported by the flexible non-electricallyconductive support material.
 19. The method of claim 18, furthercomprising transforming a data storage device of the portable electronicdevice from a first operating state into a second operating state inresponse to the detection.
 20. The method of claim 18, wherein theportable electronic device is a digital camera.
 21. The method of claim18, wherein the portable electronic device is a musical playback device.22. The method of claim 18, wherein the portable electronic device is aportable computer system.
 23. The method of claim 18, wherein the beamis rigid or flexible.
 24. The method of claim 23, wherein the second endof the beam contacts the casing when the acceleration detector is atrest.
 25. The method of claim 23, wherein the second end of the beamdoes not contact the casing during free fall.
 26. The method of claim23, wherein the acceleration detector further comprises a mass attachedto the second end of the beam.
 27. The method of claim 26, wherein themass contacts the casing when the acceleration detector is at rest. 28.The method of claim 27, wherein the mass, the casing, and the beam areeach electrically conductive.
 29. The method of claim 26, wherein themass does not contact the casing when the acceleration detector is atrest.
 30. The method of claim 23, further comprising means to couple theacceleration detector to a substrate.
 31. The method of claim 30,wherein the means is one of at least one lead or one conductive pin. 32.The method of claim 18, wherein the casing is closed at both ends andfilled with an inert gas or non-electrically conductive liquid.
 33. Adata processing system, comprising: a data storage device having datastored on a data storage medium; and an acceleration detector coupled tothe data storage device to detect a change in an acceleration of theportable electronic device and to configure the data storage device froma first operating state into a second operating state in response to thedetection, wherein the acceleration detector includes a flexiblenon-electrically conductive support material, an electrically conductivecasing coupled to the flexible non-electrically conductive supportmaterial, and a beam having a first end and a second end supported bythe flexible non-electrically conductive support material.